Working Gridless

I’m working on a font collection of ampersands and I would like to work without grid constraints to retain some of the smaller details in the designs, which were imported from some other vector software.

Question #1 - Is the best practice to put the Units Per Em at 1000 and set the grid spacing to Zero?

Question #2 - Is there a downside to distributing a font without the grid spacing, such as application compatibility or something else I have not considered?

Thanks.

There are problems if you are creating a PDF in Quark XPress, and with some old printer drivers.